The present invention relates generally to a linear displacement and support apparatus for use in a cartridge handling system, and more particularly to an apparatus for linearly displacing a cartridge engaging assembly along a predetermined displacement path and for supporting the cartridge engaging assembly at a fixed orientation relative to its displacement path.
Optical disks such as "compact disks"("CDs") are commonly used for storing musical works, as well as audio-visual works. Furthermore, due to the huge storage capacity of optical disks as compared to conventional magnetic storage media, optical disks known as "ROM (read only memory) disks" have become increasingly popular for use in the computer industry. In addition, rewritable optical disks are now being used in the computer industry. Each of these types of disks may be mounted in parallelepiped-shaped cartridges for purposes of storing and handling the disks. Also used in the computer industry for data storage are tape cartridges such as Digital Audio Tape (DAT) cartridges and 8-mm tape cartridges.
For large databases consisting of many disk or tape cartridges, it is necessary to provide a system for handling the cartridges. Various features and components of a cartridge handling system are disclosed in U.S. Pat. Nos. 4,998,232 dated Mar. 5, 1991 for OPTICAL DISK HANDLING APPARATUS WITH FLIP LATCH of Methlie et al.; 5,014,255 dated May 7, 1991 for OPTICAL DISK CARTRIDGE HANDLING APPARATUS WITH PASSIVE CARTRIDGE ENGAGEMENT ASSEMBLY of Wanger et al.; 5,010,536 dated Apr. 23, 1991 for CARTRIDGE HANDLING SYSTEM of Wanger et al.; 5,043,962 dated Aug. 27, 1991 for CARTRIDGE HANDLING SYSTEM of Wanger et al.; 5,062,093 dated Oct. 29, 1991 for OPTICAL DISK INSERTION APPARATUS of Christie et al.; 5,101,387 dated Mar. 31, 1992 for LATERAL DISPLACEMENT CONTROL ASSEMBLY FOR AN OPTICAL DISK HANDLING SYSTEM of Wanger et al.; and 5,184,336 dated Feb. 2, 1993 for LATERAL DISPLACEMENT CONTROL ASSEMBLY FOR AN OPTICAL DISK HANDLING SYSTEM of Wanger et al., which are each hereby specifically incorporated by reference for all that is disclosed therein.
In general, a cartridge handling system may include a cartridge storage system for storing the cartridges at corresponding storage locations. A cartridge handling system may also include a cartridge engaging assembly for retrieving a desired cartridge from its corresponding storage location, moving the cartridge into alignment with a disk or tape drive, and inserting the cartridge into the drive. Specifically, in a cartridge handling system wherein the stored cartridges and associated disk or tape drive are arranged in a longitudinally-extending, two-dimensional array consisting of vertically extending columns and horizontally extending rows, it is necessary for a cartridge engaging assembly to be capable of linear movement among the columns and rows. Thus, a cartridge handling system may also include an apparatus for providing linear displacement to a cartridge engaging assembly.
A cartridge handling system may further include an apparatus for supporting the cartridge engaging assembly within the cartridge handling system. "Support" of the cartridge engaging assembly as used herein refers to the functions of suspending the cartridge engaging assembly within the cartridge handling system and maintaining the stability of the cartridge engaging assembly. "Maintaining the stability" of the cartridge engaging assembly as used herein refers to the function of allowing substantially linear displacement of the cartridge engaging assembly in a desired direction while preventing undesired displacement, e.g. transverse or rotational movement.
In order to decrease production and maintenance costs and maximize the efficiency of the cartridge handling system, it is generally desirable to minimize the mass of each component of the system, including the linear displacement and support apparatus for the cartridge engaging assembly. Among other advantages, minimizing the mass of the linear displacement and support apparatus will maximize the speed with which the cartridge engaging assembly may linearly move among the columns and rows of the storage system. Specifically, in such an apparatus, it is desirable to minimize the use of relatively massive components such as leadscrews. Such a relatively massive component may also require a relatively large motor to provide sufficient driving torque, which increases the total mass of the system.
Similarly, it is generally desirable to avoid the use of costly precision tracks or rails for guidance and support.
It is also desirable to minimize the volume requirements of the linear displacement and support apparatus so that it may be mounted in a relatively small space within the cartridge handling system.
Furthermore, to control the displacement of the cartridge engaging assembly as is necessary, for example, to align it with a cartridge or drive, stability of the cartridge engaging assembly must be maintained throughout its linear displacement. In order to maintain adequate stability, it is generally desirable for a cartridge engaging assembly to be supported at multiple points on the apparatus, rather than at only one point on the apparatus. Use of a component such as a leadscrew which provides support at only one point on the apparatus may necessitate use of additional components such as rigid rails or guides to maintain the stability of the cartridge engaging assembly. Rigid rails or guides which may be used with a single-point support component such as a leadscrew must be able to support cantilever loads as well as provide accurate positional guidance.
Finally, it would be generally desirable for a linear displacement and support apparatus to be adaptable to effect either vertical or horizontal displacement of the cartridge engaging assembly. Specifically, an apparatus used for vertical displacement which relies on the downward force of gravity for any of its displacement and/or support functions could probably not be used in a horizontal orientation. Similarly, an apparatus used for horizontal displacement which would be adversely affected by the downward force of gravity could probably not be used in a vertical orientation.